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1 /* |
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2 |
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3 Copyright (C) 2000,2004 Silicon Graphics, Inc. All Rights Reserved. |
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4 |
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5 This program is free software; you can redistribute it and/or modify it |
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6 under the terms of version 2.1 of the GNU Lesser General Public License |
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7 as published by the Free Software Foundation. |
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8 |
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9 This program is distributed in the hope that it would be useful, but |
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10 WITHOUT ANY WARRANTY; without even the implied warranty of |
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11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
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12 |
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13 Further, this software is distributed without any warranty that it is |
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14 free of the rightful claim of any third person regarding infringement |
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15 or the like. Any license provided herein, whether implied or |
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16 otherwise, applies only to this software file. Patent licenses, if |
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17 any, provided herein do not apply to combinations of this program with |
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18 other software, or any other product whatsoever. |
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19 |
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20 You should have received a copy of the GNU Lesser General Public |
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21 License along with this program; if not, write the Free Software |
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22 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston MA 02110-1301, |
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23 USA. |
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24 |
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25 Contact information: Silicon Graphics, Inc., 1500 Crittenden Lane, |
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26 Mountain View, CA 94043, or: |
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27 |
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28 http://www.sgi.com |
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29 |
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30 For further information regarding this notice, see: |
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31 |
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32 http://oss.sgi.com/projects/GenInfo/NoticeExplan |
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33 |
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34 */ |
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35 |
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36 |
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37 |
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38 #include "config.h" |
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39 #include "libdwarfdefs.h" |
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40 #include <string.h> |
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41 #include "pro_incl.h" |
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42 |
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43 #define MORE_BYTES 0x80 |
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44 #define DATA_MASK 0x7f |
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45 #define DIGIT_WIDTH 7 |
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46 #define SIGN_BIT 0x40 |
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47 |
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48 |
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49 /*------------------------------------------------------------- |
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50 Encode val as a leb128. This encodes it as an unsigned |
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51 number. |
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52 ---------------------------------------------------------------*/ |
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53 /* return DW_DLV_ERROR or DW_DLV_OK. |
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54 ** space to write leb number is provided by caller, with caller |
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55 ** passing length. |
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56 ** number of bytes used returned thru nbytes arg |
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57 */ |
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58 int |
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59 _dwarf_pro_encode_leb128_nm(Dwarf_Unsigned val, int *nbytes, |
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60 char *space, int splen) |
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61 { |
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62 char *a; |
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63 char *end = space + splen; |
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64 |
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65 a = space; |
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66 do { |
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67 unsigned char uc; |
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68 |
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69 if (a >= end) { |
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70 return DW_DLV_ERROR; |
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71 } |
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72 uc = val & DATA_MASK; |
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73 val >>= DIGIT_WIDTH; |
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74 if (val != 0) { |
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75 uc |= MORE_BYTES; |
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76 } |
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77 *a = uc; |
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78 a++; |
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79 } while (val); |
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80 *nbytes = a - space; |
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81 return DW_DLV_OK; |
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82 } |
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83 |
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84 /* return DW_DLV_ERROR or DW_DLV_OK. |
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85 ** space to write leb number is provided by caller, with caller |
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86 ** passing length. |
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87 ** number of bytes used returned thru nbytes arg |
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88 ** encodes a signed number. |
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89 */ |
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90 int |
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91 _dwarf_pro_encode_signed_leb128_nm(Dwarf_Signed value, int *nbytes, |
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92 char *space, int splen) |
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93 { |
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94 char *str; |
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95 Dwarf_Signed sign = -(value < 0); |
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96 int more = 1; |
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97 char *end = space + splen; |
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98 |
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99 str = space; |
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100 |
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101 do { |
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102 unsigned char byte = value & DATA_MASK; |
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103 |
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104 value >>= DIGIT_WIDTH; |
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105 |
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106 if (str >= end) { |
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107 return DW_DLV_ERROR; |
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108 } |
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109 /* |
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110 * Remaining chunks would just contain the sign bit, and this chunk |
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111 * has already captured at least one sign bit. |
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112 */ |
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113 if (value == sign && ((byte & SIGN_BIT) == (sign & SIGN_BIT))) { |
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114 more = 0; |
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115 } else { |
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116 byte |= MORE_BYTES; |
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117 } |
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118 *str = byte; |
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119 str++; |
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120 } while (more); |
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121 *nbytes = str - space; |
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122 return DW_DLV_OK; |
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123 } |